In the public scene, nudity always carried signs. Being a symbol of vulnerability in some contexts, it may also represent the madness, freedom, the desire to shock or even an ardent appeal to be heard in some cases. This is actually the reason why activist feminist Femen movement militants are using their bodies as the main weapon of political demands by featuring themselves breast naked in their events. Despite of the visibility of the movement that now extends internationally; their methods of claims remain highly controversial and are the source of several critical. But beyond all these criticisms, what is the Femen movement telling us? What is it telling us about today’s society, on its paradoxes, its tensions and power struggles? This thesis aims to answer these questions. It is structured as follows: A first part focuses on the history of the movement, its directions and the main criticisms addressed to it. This first part is also presenting the conceptual framework of the thesis that is built around five major points: nudity as political protest tool, the image society, the body, appearance and beauty, the “spectacular urban resistance” and finally, engagement and disengagement activist. The second part presents the methodology; an ethnographic approach including semi-structured interviews with Femen activist and founder of the Quebec branch as well as the participant observation during formal and informal trainings and meetings of the group. Finally, the last section presents the results of the field. These highlight the many paradoxes and contradictions inherent in the movement, which we appear as an overview of some of the big contradictions of our society. A society of image and show. Where body, especially women’s body has gained a particular and paradoxical centrality. A society of ‘’free’’ individuals who adhere to stereotypical standards. A society in which "causes", those on the left and feminism in particular, are struggling to speak coherently, in part because of internal tensions crossings where the individual prevails too often on the collective. A society where religion is nested more than ever, blurring once again the protest lines.